1. Technical Field of the Invention
The present invention relates to a sound source apparatus with voice synthesis capabilities, which can not only produce musical tones but also synthesize a voice. The present invention also relates to a voice synthesizing apparatus capable of synthesizing multiple vocal formants to generate a synthesized voice.
2. Prior Art
To implement voice synthesis capabilities in a conventional sound source apparatus, since the conventional sound source apparatus has no function of producing voice, a separate voice synthesizing apparatus needs to be incorporated into the sound source apparatus. As an example, a prior art voice synthesizing apparatus operates on the principle that the voice of a short duration from a few milliseconds to a few tens of milliseconds is considered to be in a steady state to represent the voice as the sum of a few sine waves. There is known a voice synthesizing apparatus that resets every pitch cycle the phase of a sine-wave generator for generating sine waves to form a voiced sound, or initializes the phase of the sine-wave generator on a random basis to broaden the spectrum of the voice so as to form an unvoiced sound (for example, see Patent Document 1).
Patent Document 1 is Japanese Examined Patent Publication No. 58-53351 (Laid-open No. 56-051795).
However, the incorporation of the voice synthesizing apparatus into the sound source apparatus increases not only the size of the hardware of the voice synthesizing apparatus, but also the price of the voice synthesizing apparatus. Further, the conventional voice synthesizing apparatus can only synthesize an unreal voice of low quality.